1. Field of the Invention
This invention relates to heat-sensitive warning devices for railcar axles and more particularly, to a failed bearing indicator for indicating an overheated axle journal in a railcar axle bearing, wherein the failed bearing indicator drops from a secured to a suspended configuration from the traveling railcar in the event of overheating of the bearing, and the suspended bearing indicator strikes and activates a typically conventional dragging equipment sensor on the side of a railroad to alert railroad personnel to the overheated railcar bearing before complete failure of the bearing. In a preferred embodiment the failed bearing indicator is characterized by an elongated connector chain terminated on one end by a T-shaped connector bracket which is fastened typically by means of a heat-resistant attachment bolt to a drilled and tapped pedestal adaptor, a conventional railcar component which is typically mounted on a corresponding axle bearing of the railcar. The other end of the connector chain is terminated by a second connector bracket which is fastened to the pedestal adaptor, typically by means of a heat-sensitive release bolt. In the event of overheating of the axle bearing during travel of the railcar on the railroad, the heat-sensitive release bolt melts and releases the corresponding connector bracket from the pedestal adaptor, while the other connector bracket remains attached to the pedestal adaptor by means of the heat-resistant attachment bolt. The released connector bracket swings down from the pedestal adaptor on the connector chain and, while suspended from the connector bracket, strikes and activates the dragging equipment sensor adjacent to the railroad, to alert railroad personnel to the overheated bearing before complete failure of the bearing. The connector chain, the offset bend connector plate or connector brackets, or all three, typically has a bright, light-reflective color for enhanced visibility of the heat-activated bearing indicator in the failed position and identification of the overheated bearing. In another embodiment a rectangular offset bend connector plate is provided on each end of the connector chain in place of the connector brackets, to facilitate typically bolted attachment of the connector chain to the drilled and tapped pedestal adaptor. In still another embodiment, the connector brackets or offset bend connector plates are provided on opposite ends of an elongated, flexible connector cable instead of the connector chain.
Failed railcar bearings, which are typically caused by friction-induced heating of the rotating railcar axle journal in the stationary bearing and breakage of the axle from the bearing, frequently cause derailment of the railcar or railcars and attendant property damage, with possible injuries and deaths. In the past, railcar axle journals were fitted with oiling pads and brass bearings which have since been replaced by the modern roller bearing axle journal. While the oiling pads and brass bearings of the old axle journals squealed, smoked and finally flamed in the event of axle overheating, thus providing several warnings of an overheated axle journal before the axle broke loose from the bearing, overheating of the newer bearings is much more difficult to detect. Since the advent of the modern roller bearing journal, the railroad industry has been plagued with failed journals due to friction-induced wearing of the axle journals in the bearings, resulting in considerable property damage. The heat sensors sometimes fail to detect heat buildup from the roller bearings before they begin to fail. Furthermore, when the heat sensors do successfully detect excessive heat buildup of the bearings and properly alert railroad authorities, the sensors have not always accurately indicated which bearing or bearings of the railcar or railcars of the train are in danger of failing. After the overheated bearing or bearings have been identified by the detector, the failed bearing or bearings are typically located by counting axles rearwardly from the engine, a time and labor-intensive procedure. A limitation of the heat sensors becomes apparent under circumstances in which the sensors fail to detect an overheated journal and avoid a costly derailment or damage to the railroad. An additional detector located at the heat sensor site is designed to detect objects dragging from a moving railcar. These dragging equipment detectors are incapable of detecting overheated bearings.
2. Description of the Prior Art
A variety of devices for detecting and indicating overheated railcar bearings are known in the art. Several of these devices are detailed in U.S. Pat. Nos. 3,998,549; 4,068,811; 4,119,284; 4,316,175; 4,323,211; 4,501,006; 4,659,043; 4,812,826; 4,878,761; 4,928,910; 5,149,025; 5,100,243; 5,203,278; and 5,446,452.
An object of this invention is to provide a new and improved, heat-activated failed bearing indicator for detecting and indicating an overheated railcar axle journal in an axle bearing.
Another object of this invention is to provide a failed bearing indicator for detecting and indicating an overheated axle journal in a railcar axle bearing by heat-activated suspension of the indicator from the traveling railcar in the event of overheating of the bearing, wherein the suspended indicator strikes and activates a typically conventional dragging equipment sensor on the side of a railroad to alert railroad personnel to the overheated bearing before complete failure of the bearing.
Still another object of this invention is to provide a failed bearing indicator for detecting and indicating an overheated axle journal in a railcar axle bearing, which failed bearing indicator is reliable and yet simple in construction and installation.
Yet another object of this invention is to provide a failed bearing indicator for detecting and indicating an overheated axle journal in a railcar bearing, which failed bearing indicator is characterized by an elongated, flexible connector chain, typically having a bright or light-reflective color; a connector bracket provided on each end of the connector chain, which connector brackets may also have a bright or light-reflective color; a heat-resistant fastener engaging one of the connector brackets for fastening the connector bracket to a pedestal adaptor, a conventional railcar component mounted on each corresponding axle bearing of the railcar; and a heat-sensitive fastener engaging the other connector bracket for fastening the connector bracket to the pedestal adaptor. In the event that the axle bearing overheats due to friction-induced heating of the rotating axle journal in the stationary bearing during travel of the railcar on the railroad, the heat-sensitive bolt melts and releases the corresponding connector bracket from the pedestal adaptor, while the other connector bracket remains attached to the pedestal adaptor by means of the heat-resistant bolt. The released connector bracket, suspended from the connector chain, strikes and activates a typically conventional dragging equipment sensor adjacent to the railroad, to alert railroad personnel to the overheated bearing. The bright or light-reflective color of the connector chains, connector brackets or both facilitates quick identification of the failing bearing or bearings on the railcar or railcars.
A still further object of this invention is to provide a failed bearing indicator for detecting and indicating an overheated axle journal in a railcar bearing, which failed bearing indicator is characterized by an elongated, flexible connector chain; an offset bend connector plate provided on each end of the connector chain; a heat-resistant fastener engaging one of the offset bend connector plates for connecting the offset bend connector plate to a pedestal adaptor which is a conventional railcar component mounted on each corresponding axle bearing of the railcar; and a heat-sensitive fastener engaging the other offset bend connector plate for connecting the offset bend connector plate to the pedestal adaptor, wherein friction-induced overheating of the railcar bearing causes the heat-sensitive fastener to melt and release the corresponding offset bend connector plate from the railcar while the other offset bend connector plate remains attached to the traveling railcar, and the released offset bend connector plate, suspended from the moving railcar, strikes and activates a typically conventional dragging equipment sensor on the side of the railroad to alert railroad personnel to the overheated bearing before complete failure of the bearing.
Another object of this invention is to provide a failed bearing indicator for detecting and indicating an overheated axle journal in a railcar bearing, which failed bearing indicator is characterized by an elongated, flexible connector cable; a connector bracket or plate provided on each end of the connector cable; a heat-resistant fastener engaging one of the connector brackets or plates for fastening the connector bracket or plate to a pedestal adaptor, a conventional railcar component which is mounted on each corresponding axle bearing of the railcar; and a heat-sensitive fastener engaging the other connector bracket or plate for fastening the connector bracket or plate to the pedestal adaptor.
A still further object of the invention is to provide a failed bearing indicator which indicates a previously overheated bearing, which bearing indicator can be observed by any railroad personnel.